19 7/8" x 21 1/2" x 4" MERV 13 - Ultimate Allergen Reducing Pleated Air Filter - 6 Pack MERV 13 - Pleated Air Filter:19 7/8" x 21 1/2" x 4" MERV 13 - Pleated Air Filter Actual Dimensions: 20" x 20"

Actual Dimensions: 20" x 20" x 3/4

Actual Dimensions: 12 1/2" x 12 1/2" x 3/4"

21 1/2" x 21 1/2" x 1" Permanent Washable Air Filter - 1 Pack

They are interchangeable with 1" disposable filters and can be used again and again

19 7/8" x 21 1/2" x 4" MERV 13 - Ultimate Allergen Reducing Pleated Air Filter - 6 Pack MERV 13 - Pleated Air Filter:19 7/8" x 21 1/2" x 4" MERV 13 - Pleated Air Filter Actual Dimensions: 20" x 20"19 7 8" x 21 1 2" x 4" MERV 13 Pleated Air Filter 6 Pack Actual Dimensions: 19 7 8" x 21 1 2" x 3 3 4" Filtration Group's High Capacity MERV 13 air filter is made of 100% Synthetic Media which will not promote mold or bacteria growth and has the following features: MERV 13 Efficiency, LEED compliant, High Efficiency in 2" depth, Advanced media incorporating both charged fibers and traditional mechanical principles, 100% recycled paperboard frame, Easy